Material treating apparatus



April 30, 1946. L, s. PETERSEN MATERIAL TREATING APPARATUS Filed April 10, 1944- 5 Sheets-Sheet 1 WENTOR fiisw ATTORNEY;

April 30, 1946. I s PETERQSEN 2,399,570

MATERIAL TREATING APPARATUS Filed April 10, 1944 5 SheetsSheet 2 \N NTOR BY fiance M M all/ dr ATTORNEY;

April 30, 1946.

L, s. PETERSEN MATERIAL TREATING APPARATUS Filed April 10, 1944 3 Sheets-Sheet 5 ATTORNEY 5 Patented Apr. 30, 1946 MATERIAL TREATING APPARATUS Louis S. Petersen, Forest Hills, N. Y., assignor to F. L. Smidth 80 Co., New York, N. Y., a corporation of New Jersey Application April 10, 1944, Serial No. 530,434 9 Claims. (Cl r 263-22) This invention relates to the treatment of finely divided materials for indirect cooling or heating purposes, and is concerned more particularly with a novel apparatus of the type described in which the materials undergoing treatment are kept from contact with the surrounding atmosphere. The apparatus of the invention may be employed in numerous applications, as, for example, in the cooling of ores roasted in a kiln. As the form of the apparatus suitable for that use is typical, it will be illustrated and described in detail for purposes of explanation, although it will be apparent that the utility or the invention is not limited to that specific adaptation.

In the cooling of roasted ore issuing from a kiln, one type of cooling apparatus that has been successfully employed includes a plurality of cooling chambers mounted on the outside of the kiln near its lower'end and connected to the interior of the kiln to receive the material therefrom. Each such chamber has-an inlet at one 'end and an outlet at the other and, as the cham er rotates with the kiln, the material moves through the chamber from the inlet to the outlet. In some cases, the inlet of the chamber isadjacent the lower end of the kiln and' the material moves upwardly through the chamber, such movement being efiected by stationary screw flights within the chamber. In other constructions, the inlet of the chamber is at the higher end, in which event the material will move through the chamber by gravity and the screw flights need not be employed, although they may be used, if a positive feed of the material is desired.

In such cooling apparatus in which the cooling action is indirect and the cooling medium is applied to the outside of the chambers and does not come into direct contact with the material, it may be desirable to keep the material from contact with the surrounding atmosphere. In kiln operation, the zone of the kiln from which the material passes into the cooler is at sub-atmospheric pressure and means must, accordingly, be provided at the discharge end of each coolin chamber to permit the ore to leave the chamber while preventing air from entering and passing through the chamber into the kiln, if the material ls to be kept from contact with the atmosphere. Heretofore, the discharge means for the purpose have usually included hinged closures normally closed but opened at the proper. time in each rotation of the cooling chamber by levers, cams. rails, and similar means. Suchmechanicallycpereted closures, if eflective fortheirintended purpose, are likely to be complicated and are subject to rapid wear, particularly if the materials being handled are dusty and abrasive in character.

The present invention is, accordingly, directed to the'provision of a novel apparatus for the indirect cooling or heating of finely divided materials, which includes discharge means which keep the materials from contact with the surrounding atmosphere during treatment and are not subject to the disadvantages of the mechanically operated closures heretofore used. The new apparatus comprises a treating chamber through which the material passes and a rotary discharge spout which includes a convolute passage having a wall along which the material travels as the spout rotates. The passage is of such size relative to the volume of material being handled that the material ordinarily does not completely fill the passage at any point, and the flow of air through the passage along the surface of the traveling material is prevented by means mounted across the passage to make contact with the traveling material and close that part of the passage not occupied by the material. The means referred to offer no substantial resistance to the travel of the material but effectively prevent the entrance of the atmosphere into the interior of the chamber.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which Figure 1 is a view, partly in vertical section and partly in elevation, of a portion of a kiln equipped with the new cooling apparatus;

Figure 2 is an end elevation of the apparatus shown in Figure 1;

Figure 3 is a view, partly in vertical section and partly in elevation, of a part of a cooling chamber of the invention equipped with the novel discharge spout;

Figure 4 is a sectional view, with parts omitted, on the line 'A-A of Figure 3;

Figure 5 is another sectional view on the line AA of Figure 3, showing certain of the parts omitted in Figure 4 and omitting parts shown in Figure 4;

Figure 6 is a sectional View, on the line 6-43 of Figure 7, of a modified construction; and

Figure 7 is a sectional View on the line l'-E of Figure 6.

In the drawings, the apparatus of the invention is illustrated as including a plurality of cooling chambers I0 mounted on the shell of a rotary kiln-l I near its lower end. The'kiln is of conventional construction and it is provided with openings l2 in its lining l 3 and hell l4, through which material may pass into elbows l5 leading to the respective chambers l0.

Screw flights IS on a shaft I! are mounted in each chamber and one end of the shaft is suitably supported at l8 at the inlet end of the chamber. At its outlet end, the chamber is provided with a flange IE! to which is attached a corresponding flange on a discharge'spout. The spoutcomprises a chamber having a portion 2| into which the shaft I! with the screw flights projects, the end of the shaft being supported in a cross member 22 within the chamber. A discharge elbow 23 extends outwardly from the wall of the chamber 20 and is provided at its end with a flange 24 to which is connected a corresponding flange 25 on a housing 26 which is hollow and helical in shape. The housing defines a convolute passage, in this case, of helica] form, through which the material travels along the outer wall 21 as the cooling chamber and spout rotate.

In the operation of the kiln, the material traveling downwardly through it passes into the cooling chambers I0 and is advanced through each chamber by the action of the screw flights therein to be discharged into chamber 20 of the discharge spout at the end of the coolingchamber. As the spout rotates to a position in which the entrance to its elbow 23 is at the bottom of chamber 20, the material in that chamber enters the elbow and then enters and travels along the passage through housing 26, as the rotation of the spout continues. The introduction of material into the spout is intermittent and the volume of the material entering the spout in each such operation is ordinarily insufllcient to fill the passage in housing 26 completely, as indicated by the dotted lines 28 showing the material level in elbow 23 and the passage through housing 26.

The flow of air backward through the passage in housing 26 into chamber 20 and the cooling chamber I0 is then prevented by means cooperating with the material traveling through the passage. The means shown for that purpose take the form of plates 29 mounted on the wall 33 of the passage lying opposite to wall 21 along which the material travels. The plates extend partway across the passage at an angle toy and in the y direction of flow of the material and their length is such that they enter the traveling material, so that the plates and material cooperate to close that part of the passage not occupied by the material. Also, the wall 3! of the elbow 23, which lies opposite to wall 32 along which the material travels, is inclined toward wall 32 so as to close that part of the elbow not occupied by material.

At its outer end, the housing 26 is open so that the material may discharge therefrom when the spout reaches the position 33 (Fig. 2). The material so discharged enters a chute 34 through which it is conducted to a desired delivery point.

At a convenient point in the loath of travel of the cooling chambers, a cooling medium is discharged thereon, as by mean of a spray pipe 35. Cooling also occurs by radiation as the chambers rotate.

A modified spout construction is illustrated in Figs. 6 and 7, and this spout includes a housing 36 provided with a flange 31 that may be secured to the flange 38 at the end of the cooling chamber 39. Within the housing is a spiral partition 40 which, with the side walls of the housing, defines a passage 4| through whichthe material travels to an outlet 42. Within the housing is a crossbar structure 43 in which the end of shaft 44 having screw flights 45 is supported, the shaft extending through the cooling chamber 39 from end to end thereof. A plate 46 is mounted at the inner end of the partition and it serves to prevent material about to enter passage 4| from backing up and returning to the surface 40a of the inmost convolution of partition 40.

In the operation of the cooling apparatus described, the material issuing from the kiln enters the upper end of cooling chamber 39 and, as the chamber rotates with the kiln, the material is advanced along the chamber positively by the action of the screw flights 45. At the end of the chamber, the material enters the housing 36 and is deposited on the surface 40a of the inmost convolution of partition 40. The kiln rotates clockwise so that the material slides along the inner surface of partition 40 through the several convolutions thereof to the outlet 42. When the spout reaches the position corresponding to position 33 in Fig. 2, the material issues from the outlet.

The material is discharged intermittently into the spout and each. discharge is insufficient in volume to fill the passage defined by the convolutions of the partition 40, the level of the material in the passage being indicated by the dotted lines 41. In order to prevent air from being drawn into the spout through the outlet 42, the outer wall of the partition is formed with the plurality of plates 48 illustrated as integral with the partition. These plates extend across the passage defined by the partition at an angle and they are inclined in the direction of travel of the material. As the material moves through the passage, it flows around the free edges of the plates and the plates are of such length as to lie beneath the level of the material. The plates and the material thus cooperate to close that part of the passage not occupied by the material and thus seal the passage against inflow of air. v

In the constructions illustrated, the cooling chamber is shown as mounted on a kiln with the material entering the chamber at the upper end and discharging at the lower end. With this arrangement, the material will travel throughthe cooling chamber by gravity as the kiln rotates, and the screw flights are not necessary, although they may be desirable to insure positive flow. In some cooling apparatus of this type, as heretofore used, the material enter the cooling chamber at the lower end and travels upwardly to be discharged at the upper end. With such an arrangement, the screw is necessary because of the upward travel of the material. The cooling apparatus of the invention may be employed in that manner by mounting it on the kiln in a suitable fashion and making use of screw flights which will have the desired effect.

In the application of the new cooling apparatus to a kiln, the cooling chamber is rotated, the spout is mounted fast on the end of the cooling chamber, and the screw flights have no movement relative to the chamber. It will be apparent, however, that rotation of the cooling chamber is not necessary and the material may be advanced through it by rotation of the screw. In such a construction, the spout will be rotated with the screw in order that the material may advance through the spout and be discharged.

I claim:

1. An apparatus for treating finely divided material, which comprises a chamber having an inlet for material at one end and an outlet at the other, and a rotary discharge spout at the outlet end of the chamber and receiving material therefrom, the spout including a convolute passage having a wall along which the material travels as the spout rotates, and mean within the passage entering the surface of the material and closing that part of the passage not occupied by the material, said mean being distributed along the length of the passage.

2. An apparatus for treating finely divided material, which comprises a chamber having an inlet for material at one end and an outlet at the: other, and a rotary discharge spout at the outlet end of the chamber and receiving material therefrom, the spout including a convolute passage having a wall along which the material travels as the spout rotates, and means on the opposite wall of the passage extending toward the first wall and adapted to enter the traveling material and, with the latter, close the passage.

3. An apparatus for treating finely divided material, which comprises a chamber having an inlet for material at one end and an outlet at the other, and a rotary discharge spout at the outlet end of the chamber and receiving material therefrom, the spout including a convolute passage having a wall along which the material travels as the spout rotates, and a plurality of plates along the opposite wall of the passage and extending toward the first wall, the plates being adapted to enter the traveling material and, with the latter, close the passage.

4. An apparatus for treating finely divided material, which comprises a chamber having an inlet for material at one end and an outlet at the other, and a rotary discharge spout at the outlet end of the chamber and receiving material therefrom, the spout including a convolute passage having a Wall along which the material travels as the spout rotates, and a plurality of plates spaced along the opposite wall of the passage and extending toward the first wall at an angle to and in the direction of the travel of the material, the plates being adapted to enter the material and, with the latter, close the passage.

5. An apparatus for treating finely divided material, which comprises a rotary chamber mounted on a generally horizontal axis and having an inlet for the material at one end and an outlet at the other, and a discharge spout mounted on the chamber at the outlet end of the chamber to receive material issuing therefrom, the spout including a convolute passage having a wall along which the material travels as the chamber rotates, and means on the opposite wall of the passage and extending toward the first Wall and adapted to enter the traveling material and, with the latter, close the passage.

6. An apparatus for treating finely divided material, which comprises a rotary chamber mounted on a generally horizontal axis and having an inlet for the material at one end and an outlet at the other, and a discharge spout mounted on the chamber at the outlet end of the chamber to receive material issuing therefrom, the spout including a spiral passage having a Wall along which the material travels as the chamber ro tates, and means spaced along the opposite wall of the passage and extending toward the first wall, said means being adapted to enter the traveling material, and, with the latter, close the passage.

7. An apparatus for treating finely divided material, which comprises a rotary chamber mounted on a generally horizontal axis and having an inlet for the material at one end and an outlet at the other, and a discharge spout mounted on the chamber at the outlet end of the chamber to receive material issuing therefrom, the spout including a passage having a plurality of convolutions and a Wall along which the material travels as the chamber rotates, and means spaced along the opposite wall of the passage and xtending toward the first wall, said means being adapted to enter the traveling material and, with the latter, close the passage.

8. An apparatus for treating finely divided material, which comprises a chamber having an in-- let for material at one end and an outlet at the other, means within the chamber for advancing the material from the inlet to the outlet, and a rotary discharge spout at the outlet end of the chamber and receiving material therefrom, the spout including a convolute passage having a wall along which the material travels as the spout rotate and means spaced along the opposite wall of the passage and extending toward the first wall, said means being adapted to enter the traveling material and, with the latter, close the passage.

9. An apparatus for cooling finely divided material burned in a kiln, which comprises a chamber mounted lengthwise on the outside of the kiln and having an inlet at one end receiving material from the kiln and an outlet at the other end, and a discharge spout mounted on the hamber at the outlet end thereof and receiving material therefrom, the spout including a convolute passage through which the material travel as the spout rotates with the kiln, and means in the passage adapted to enter the surface of the traveling material to close that part of the passage not occupied by the material, said means being distributed along the length of the passage.

LOUIS S. PETERSEN. 

